The present invention relates generally to the treatment and handling of gases discharged in various industrial processes, and more particularly, is directed to a novel pressure generator and/or gas scrubber.
Because various industrial processes generate contaminated gases, systems are required for treating and handling the discharged gases to prevent contamination of the atmosphere and/or to render the gases usable with heat recovery equipment employed in these processes. Thus, for example, various gas scrubbing devices, such as venturi scrubbers, plate towers, packed-bed scrubbers, mobile-bed scrubbers, spray scrubbers, cyclone scrubbers, mechanical scrubbers, fiber-bed scrubbers, electrically augmented scrubbers and the like are known. For example, venturi scrubbers are widely used for collecting fine and submicrometer solid particulate, condensing tars and mists, mixtures of liquids and solids.
In a venturi scrubber, a venturi tube is provided. Gas is supplied by a fan, blower or the like through the venturi tube, and a liquid, such as water, is supplied to the throat of the venturi tube in a direction transverse to the gas flow. Accordingly, at the throat, the water is atomized so as to collect the particulate matter in the gas. Thereafter, the atomized water containing the solid particulate, and the gas, are supplied to a cyclone separator to separate the gas from the water and solid particulates therein.
However, the use of venturi (and other) scrubbers in a power plant, for example, is extremely undesirable. This is because of the large pressure drop over the scrubber, primarily due to the supply of water to the throat of the venturi tube. In other words, the water supplied transverse to the direction of gas flow provides an increase in pressure drop. As a result, it is necessary to provide a fan, blower or the like to generate the necessary pressure to accelerate the gas through the venturi scrubber. This is, in turn, results in a substantial power consumption. As an example, a 6,000 H.P. fan motor may be necessary for a twelve-foot diameter venturi tube which is fifty feet long.
In a power plant of the aforementioned type in which coal is burned to produce electricity, there is an approximately 80% efficiency in such conversion. However, with the use of a venturi scrubber, there is a further drop of 5% to 6% in such efficiency over the entire power plant installation, resulting in millions of lost dollars. This is because an additional fan motor is generally required to drive the gases through the power plant. For example, in the boiler for coal conversion, there may be a 10" H.sub.2 O pressure drop, with an additional 20" H.sub.2 O pressure drop across the venturi scrubber. This would then require a fan motor at the output of the cyclone separator sufficient to create a pressure of 30" H.sub.2 O to compensate for the aforementioned pressure drops. This, however, results in a large reduction in the efficiency of the power plant.